Mortar mixer



Feb. 18, 1936. D. MILLER MORTAR MIXER Filed April 25, 1932 3 Sheets-Sheet 1 INVENTOR e m 4 0 we 6 3 Sheets-Sheet 2 NVENTOR Zuni 770 0 1% er Feb. 18, 1936. D. MILLER MORTAR MIXER Filed April 25, 1932 Feb. 18, 1936. E 2,031,326

MORTAR MIXER Filed April 25, 1952 3 Sheets-Sheet 3 l 1 ll)!" ,H H

. I INVENTOR Zargwdv/Yz'l Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE MORTAR Dnrando Miller, Pclliam Manor. 8. 1.

Application April 25, 1932, Serial No. 607, 82

3 Claims. 83-73) This invention relates to improvements in the method of and apparatus for use in handling and mixing mortar and similar building materials.

The requirements of present day building operations are such that the large quantities oi mortar and likev plastic materials used can more economically be supplied premixed in truck load lots, from a plant having eilective mixing equipment and suitable storage space.

The mortar as delivered'is a wet mixture of suitably aged slacked lime and sand to which before use cement is usually added in proportions varying with the use. It is important that cement should be added only at the time oi use 5 for the reason that the cement sets it too long an interval intervenes after the wetting thereof.

It is also important that the cement should be added in proper proportion, fortoo little will cause inferior work and too much involves use- 20 less expense andin some cases unsatisfactory results.

The present invention has for its principal object to provide an apparatus adapted to receive bulk quantities of lime mortar and of cement 25 and besides to mix the necessary cement with the lime mortar as the material is required, whereby the lime mortar can be kept. for an indefinite period in moist condition and mixed with cement and delivered as necessary.

30 Another object is to provide a device particularly adapted to receive truck load lots of ready mixed lime mortar or other similar materials which may be dumped directly from the truck into the apparatus for regulated delivery to small- 35 er trucks or wheelbarrows.

A further object of the invention is to provide a system foreconomically and readily supplying lime and cement mortar for brick work, plaster and similar construction by which truck loads 0 of the respective substances can be delivered into suitable hoppers from which these materials will be fed in suitable proportions and mixed, suitable automatic controls being provided whereby accidental variations in the fixed proportion and other results of human carelessness are reduced to a minimum.

The invention is further designed to provide an automatic control so insuring the regulated delivery of the respective ingredients of a plastic 'mass as to stop the delivery of all ingredients upon the failure of one.

Another object is to provide an apparatus for delivering automatically controlled ready mixed 55 unit quantities of lime cement mortar from batch deliveries, which apparatus will require a minimum of manual labor or control.

Further objects and advantages of this invention will appear from the following description thereof taken in connection with the attached 5 drawings which illustrate a preferred form of embodiment and in which:

Figure 1 is a diagrammatic side elevation showing the relative location of a delivery truck and the apparatus to be described; 10

Figure 2 is an elevational view with parts of the mixing apparatus broken away to show the interior construction:

Figure 3 is a top plan view 01' the hopper shown in Figure 2;

Figure 4 is an end elevation of the hopper shown in Figure 2;

Figures 5, 6 and 7 are detailed vertical see tional views taken on the lines 5-5, 6--6, and 1-1 of Figure 2 respectively;

Figure 8 is a horizontal section through the cement hopper chute taken substantially on the line 0-8 of Figure 5, and; c

Figure 9 is a schematicwiring diagram of the apparatus.

Theapparatus shown in the drawings for the purposes of illustration provides for the convenient discharge of truckload lots of wet mixed and aged lime mortar and of dry cement. The apparatus may be arranged to receive such materials from trucks driven into the first door of a building in which the apparatus is installed. As

' indicated in Figure 1, a mortar mixer In is in stalled directly beneath the ground level floor I2,

so that a truck Il may drive into the building as in common practice and discharge the lime mortar I through suitable openings I8 in the floor directly into auxiliary hoppers 20 built about the mortar mixer. As such trucks are usually provided with a chute l5 through which the 40 material is discharged, it is to be understood that all manual handling of the mortar will be avoided by merely driving the truck into the building and discharging the entire truck load.

The mortar mixer III illustrated in Figure 2 in greater detail is preferably provided with a mortar receiving chamber or hopper 22 which as shown in Figure 4 is relatively deep and suiiiciently v shaped for efiective operation. The bottom 23 is of cylindrical channel shape and is provided with a screw conveyor 24 which may be driven in any suitable manner from the motor 26. As the screw conveyor 24 is rotated the mortar will be discharged from the end 01' the storage chamber 22 through the shield 10 which sirable to provide a cement receiving receptacle 32 which may similarly have a false hopper It to be filled directly from the street level fioor. Bulk cement, ordinarily dry cement, may be delivered in truck load lots and such hopper will cooperate with the mixer hopper I! to hold an entire lot. As shown in Figure 4 the cement hopper 32 is similarly substantially V shaped with a cylindrical channel bottom and is similarly provided with a discharge screw N. The screw 34 will discharge in the opposite direction to the screw 24 and will discharge cement through the chute it into a mixing chamber a which is provided with a paddle type of mixer ll. The cement chute II is provided with a pivoted door 42, the

25 operation of which will be discussed hereinafter.

If desired the cement hopper 82 may be divided by partitions with two cmnpartments so that both lime and cement may be delivered therefrom in measured amounts.

The cement hopper 32 is provided with a shield or cover 44 of semi-cylindrical shape positioned over the discharge end portion of the screw 34 to prevent the direct e of cement through the cement chute I. and to insure thepassage of 35 a predetermined amount of cement out of the chute at each turn of the screw. The construction of this cover may be as shown in Figure for example.

Referring again to Figure 2 the motor 20 may 40 be connected by means of a chain I. or other gearing to the main shaft I which drives the paddle mixer 40. The shaft II also carries the clutch member I: which drives the clutch member 83 and through the chain N, the counter shaft which extends to the extreme end of the mixing device, at which point it is connectedbymeansofachainli orsimilargearingto the cement conveyor screw II. The clutch member 53 is also directly secured to the hollow shaft 50 of the mortar measuring and discharge screw 24. The clutch lever I1 is arranged to operate the clutch member l8.

The operation of the device is as follows: The

mortar hopper 22, andthe cement hopper II 50 being filled, the motor is started with the clutch engaged so that the screw conveyor 34 and discharges cement and the screw conveyor ll discharges predetermined amounts of lime mortar simultaneously into the mixing chamber 38 and in the proportions depending upon the gear ratio. As the material is discharged into the mixing chamber II the paddle ll thoroughly intermixes the substances and slowly moves the material toward the discharge chute II. This is the 65 preferred construction by which the mortar is mixed simultaneously by the operationof the feed screws and the mixing paddle, the blades of the mixing paddle being curved to facilitate said discharge from the mixing chamber.. After a sufiicient amount has been delivered the clutch lever U is thrown to disengage the clutch member, thereby simultaneously stoppins the mortar feed screw-ll and the cement feed screw 34. The mixing paddle continues to rotate, however, as

75 long as the motor operatu continually discharg ing the mixed mortar and cement until the mixingchamberlsemptv. Bymeansofasuitable electric switch II the motor may then be stopped as well.

In order to proportion the ingredients dis- 5 charged into the mixing chamber, it is necessary to properly control the rate of rotation of the two screws 24 and M. This may be done by the proper use of gears ll and II over which the chain It operates as is well'known in the art. 10 Other arrangements may also be used as desired, it being possible to change the mix of the respective ingredients from one proportion to another.

To insure the continuous delivery of cement in the proper amounts, the chute 88 is provided 15 with a door 42 more clearly shown in l 'igures 5 and8,inwhichthedoorish ingcdtoasuitable fixedhingedpinflaontheendofwhichis carried an electric control I. One diagrammatlc method of operation of this control Cl is 20 showninFigureiLinwhichthecimtrolllis shown as provided with a mercury switch, closing the circuit to the motor control rheostat 82 by holding the control lever 04 in position to close the circuit to the motor it through the 26 medium of a suitable solenoid a. As long as the motor 26 is running and cement is being delivered through the chute It. the door I! is held open by the discharge from the chute. If after the motor starts, the cement does not imso mediately discharge from the screw II, or if after starting the motor the fiow of cement from the hopper 32 ceases due to the hopper not being kept full, the door I! will close, thereby tilting the mercury control switch Cl and breaking the 35 holding circuit through the solenoid a, permitting the motor control arm 04 to move under the action of spring Mb to the of! position which stops the motor. The switch OI adjacent the end of the discharge chute for the purpose of so controlling the motor when sufficlent material has been discharged into the wheelbarrow 3., may suitably be incorporated in this holding circuit. It is to be understood that this circuit and the manner by which the motor is stopped when to cement ceases to fiow through the chute 86 is purely diagrammatic and is susceptible to variations which are well known to the art. As the screws 24 and 34 .are designed and driven to feed regulated and measured amounts of lime mortar and cement into the mixing chamber SI and through the change gear control ratio I, I. and It, can be regulated to deliver different ratios (1 cement. The automatic stopping of the apparatus when the fiow of cement through the chute 66 It ceases, prevents the making of improper mixes, so that once the gear ratio for a particuiarjobhasbeensetaocordingtospecifications allmixes deliveredfromthemachinewillbeof thatratio. 00

The doorOLbycIosiMthsoutletflalsoprevents the moisture in the mixing chamber from affecting the cement in the hopper when the cementisnotbeing fed.

Forthepurposeoffacilitatingcleanhnofthe charged are also provided with water tions is by which water maybeintroduoed directl into the chambers if desired, towalh the chambersm-toaddtheneceaarywatertothe mix. Itistobeunderstoodhowevmtintwatsr Tl is normally introduced only into the mixing chamber 38, as the lime mortar is normally sumciently moist to be conveyed by the screw 24. The shield Ill for the lime mortar and the shield 44 as shown in Figure for the cement makes the screw conveyors proper measuring devices, so that the precise amount of material discharged may be controlled.

If cement is delivered in bags it is possible to remove the false hopper 33 and position a man adjacent the mixing compartment 32 so that the cement may be dumped into the mixing chamber as desired. Normally, however, it is preferred to use both compartments together as described. 7

While the apparatus has been described as operating with lime mortar and cement it would also be possible to mix other similar suitable materials such as dry sand, lime and cement, sand, cement and aggregate and by varying the size or operating speed of the conveyors to get any desired proportions in the mix, if an aggregate were used as in the making of concrete it would be necessary to provide a conveyor which would suitably carry the aggre ate. The apparatus may also be used to dispense straight cement or straight lime mortar in measured quantities without any mixing operation.

While I have shown preferredforms of embodiment of my apparatus modifications may be made therein and changes of construction resorted to without departing from the spirit and scope of my invention.

I claim:

1. Amaterial mixing apparatus comprising in combination a mixing chamber, a hopper for bulk material with an outlet discharging into the mixing chamber, a second hopper for bulk material discharging into the mixing chamber, a horizontal feed screw positioned in the bottom of the first hopper having a central tubular shaft, feed means in the bottom of the second hopper for feeding material to the mixing chamber. an agitator for mixing the ingredients of the mixing chamber co-axial with the feed screw of the first hopper and having a shaft extending through the tubular shaft of the feed screw, a driving means connected to the agitator shaft, a clutch and means controlled by said clutch for actuating both the feed screw and the feed means in synchronism to deliver materials to the mixing chamber in predetermined proportions.

2. A portable mortar mixer for receiving in temporary storage, proportionating, mixing and discharging a lime mortar consisting of hydrated lime and cement which comprises a plurality of hoppers, normally adapted to receive truck load lots of hydrated lime and cement respectively, and a mixing chamber below the cement receiving hopper and adjacent the end of the hydrated lime receiving hopper, proportionating feed screws in the bottom of the respective hoppers, a common drive means for said feed screws, means adjacent the discharge of the respective feed screws to accurately proportion the unit discharge per rotation of the respective feed screws and control means adjacent the discharge of the cement hopper controlling the feed screw driving means to stop the feed on failure of discharge from the cement hopper and a non-continuous mixing paddle in the mixing chamber normally driven in synchronism with the feed screw driving mechanism and means to separately stop the feeding mechanism of the feed screws while continuing the rotation of the mixing paddle whereby the mixing chamber will continuously rotate to mix and discharge the chamber after the feeding mechanism has stopped.

3. A portable material mixing unit of the class described, comprising in combination, a plurality of hoppers for bulk material, said hoppers being in side by side relation, feed screws in each of said hoppers for discharging proportionated quantities of material therefrom, and a mixing chamber in direct communication with one of said hoppers and a substantial continuation thereof, said mixing chamber having an opening therein in direct communication with said hopper to receive material discharged therefrom, another of said hoppers being above the mixing chamber and having an opening therein above the mixing chamber and adjacent the first mentioned opening whereby the respective feed screws will discharge materials into the same end of the mixing chamber, and an agitator in the mixing chamber to mix and progressively discharge mixed materials from the end opposite the receiving end of said mixing chamber and driving means connected to the agitator and to the respective feed screws, said driving means including clutched driving connections between a power source and the agitator whereby said agitator may be separately operated when said feed screws are declutched to prevent further feed.

DURANDO IMIILER. 

